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Abstract
Geopolymer cements provide an alternative to the Portland cement used to manufacture structural concrete. The material commonly used to produce geopolymers is fly ash, which is found in the waste stream of power generation facilities. Therefore, replacing Portland cement with geopolymer cement improves the sustainability of concrete by reducing emissions and diverting waste from landfils. In this study, geopolymer cements were used to create concrete having compressive strength in the range of 5,000 to 12,000 psi (34-83 MPa). The mechanical properties of these concretes were evaluated to determine the compressive, tensile and elastic behaviors. Durability tests were also performed to assess creep and shrinkage characteristics. Prestressed and mild steel reinforced beams were made with the geopolymer cement concrete (GCC) and were tested to failure. The results of these flexural tests were used to confirm the applicability of traditional concrete design criteria and techniques. The GCC was found to perform in a similar manner to Portland cement concrete and the efficacy of existing design formulations was verified with small changes to some design values. Finally, the processes and materials used to prepare the concretes were used to make a preliminary lifecycle assessment to verify the sustainability gains of GCC. Reduced energy use and emissions generation were confirmed.